Process and apparatus for spinning artificial silk



Aug. 7, 1934. H. A. SCHRENK 1,963,912 PROCESS AND APPARATUS FOR SPINNINGARTIFICIAL SILK Filed May 23, 1933 3Sheefs-Sheet 1 mam/foo H. A. sssssNK 1,968,912 PARATUS FOR SPINNING ARTIFICIAL SI H. A. SCHRENK r1,968,912

PROCESS 'AND APPARATUS FOR SPINNING ARTIFICIAL SILK Filed May 23, 1933SSheets-Sheet 3 Patented Aug. 7, 193

UNITED STATES raocnss AND APPARATUS FOR SPINNING ARTIFICIAL SILK HansAlwin Schrenk, Arnhem, Netherlands, as-

signor to American Enka Corporation, N. 0., a corporation of DelawareEnka,

Application May 23, 1933, Serial No. 672,416 In Germany March 23, 193226. Claims.

Theinvention relates to a process and apparatus forchanging the tensionof a freshly spun artificial thread.

- One object of the invention is to attain a gradually increasingtension and thus a stretching step by step of the thread.

Another object of the invention is to attain a gradual decrease of thetension and thus a shrinking step by step of the thread.

According to an other form of the invention several steps of .tensioningand slackening of the thread can follow one another.

, In the manufacture of artificial silk from cellulosic solutions, thespinning solution is extruded through a spinning nozzle into or througha coagulating or precipitating solution according to the particularprocess involved. The formed filaments, which are still in plasticcondition, are then carried to a collecting means and wound into yarnbodies.

During the spinning operation it has been the usual practice to impartto the filaments a stretching action by collecting the filaments at agreater speed than the speed of extrusion from the spinning nozzle. Thisstretching action on the freshly made filaments not only gave a finerdenier but also increased the tensile strength.

With this method of' imparting stretch it was found that control of thestretching action was difficult of achievement due to variations in theperipheral speed of the yarn body at different points of itscircumference. In view of the aforementioned difliculty, various othermeans have been used which considerably improved the uniformity of thestretching action. The -means mentioned included stationary guide rodsand other guiding means which would act to retard the passage of thethread and thus create a stretching action. In practice, however, it hasbeen found that these thread guides, though they imposed a tension andwere an improvement over the first mentioned method, were still notsatisfactory in that an irregular tension resulted. The use of powerdriven rollers running at different peripheral speeds, over which thethreads passed, has. been tried with varying degrees of success in the.stretching of the threads. With these last mentioned means, uniformityof the stretching action was attained but not a uniform thread.

The purpose of the present invention is to overcome the difficultiesmentioned above by imparting to the filaments changes in tension whichare imparted by a. method and means operated by the passage of thethreads themselves during the spinning operation or at any stage wherethey are in a plastic condition. These means include surfaces, at leastone of which has different diameter guiding surfaces, over which thethreads are passed alternately from one surface to another a pluralityof times and which are actuated solely by thread contact. By use ofthese filament driven surfaces, the stretching action is found to beuniform and the threads are allowed to compensate within themselves forany variations in the operating conditions.

The invention is also suited to imparting a stretch and contractingaction during the passage of the thread over the rollers or it ispossible to obtain an increasing contraction of the filaments. Theselatter arrangements are for producing threads having different tensilestrengths and elongation characteristics. It is a well known principlethat, within certain limits, the greater the stretch during the spinningof artificial filaments the less will be the elongation. 76

It is therefore readily apparent that threads with the greatest strengthmay have the least elongation, and vice versa. For certain uses a.thread of comparatively little strength and having high elongation maybe desired in preference to one 80 of greater strength with lowelongation qualities; Whereas threads. having maximum thread strength incombination with maximum elongation are preferable in other respects.These qualities are given to the threads mainly through means forvarying the tension during spinning. It is the purpose of applicant'sinvention, as hereinbefore pointed out, to achieve these differenttension results in a novel manner and whereby the threads receive a lessrigid stretching action than heretofore in the art. I

It has also been found that, due to the use of applicant's stretchingmethod and apparatus, filaments of improved and uniform dyeingcharacteristics have resulted. Dyeing difficulties are caused by variedspinning conditions which the invention overcomes by the use of threaddriven means which allow the threads to become selfcompensating duringthe varied stretching step.

According to the invention the freshly spun artificial thread isconducted over two or more rollers, each roller consisting of aplurality of guiding surfaces in the form of grooves having the same ordifferent diameters. If the diameter of the thread. guiding groovesfollowing each other in the run of thethread is increased step by step,then a continuous stretching of the thread is vattained. If, on theother hand, the diameter of these rollers, is decreased, then-aslackening of the thread and shrinking is at-- 119 tained. Thedimensions of the guiding grooves can, of course, also be selected insuch a way that the thread is subject to stretching and also toslackenings. Furthermore it can be imagined that a stretching or aslackening of the thread can be produced by some 01 the grooves only andthat the other grooves are only used for lengthening the path of thethread requisite for a finished thread formation.

The series of rollers-under certain circumstances there are more thantwo-can be situated both inside the spinning bath or partly inside andpartly outside the spinning bath. They can also be so arranged that thethread only makes its path through the air In using the apparatusaccording to the invention the iormation oi. the thread is done rapidlyand demands the smallest space. This is especially of importance inspinning according to the continue process.

In many cases it can be preferable to use instead of the rollers havingseveral guiding grooves or in combination with such a roller or rollersone or more separate freelyrotating rollers.

Inthe drawings two forms of execution oi the apparatus according to theinvention are represented.

Fig. 1 shows the front view, of the apparatus.

Fig. 2 shows the side-view of the apparatus.

Fig. 3 shows a detail.

Fig. 4 shows another form of execution in front View.

Fig. 5 shows the same in side view.

Fig. 6 is a diagrammatic view illustrating the path the threads aregiven over the rollers when each succeeding guiding surface in the path03 the thread has a greater diameter resulting in imparting to thethread a successive stretch.

Fig. '7 is a view similar to Fig. 6 in which each succeeeding guidingsurface in the path 05. the

. thread is of a lesser diameter, thereby imparting to the thread asuccessive lowering of its linear speed and allowing a successivecontraction.

Fig. 8 is a view similar to Figs. 6 and 7 in which the threads haveimparted thereto an alternate stretch and contraction by alternatelypassing the threads to surfaces 01 greater and lesser peripheral speeds.

The apparatus according to Figs. 1 and 2 consists of a holder 1 and thetwo rollers 2 and 3, which are mounted on bolts 4 and 5 respectively.The bolt 5 is attached to a slide 6, so that the distance between therollers 2 and 3 and thus the length of the path of the thread ischangeable.

Each roller is the combination of four thread guiding grooves 7, 9, 11and i3 and 8, l6, l2 and 14 respectively. In this form oi. execution thediameter of these guiding grooves is chosen in such a manner that thethread leaving the jet 15 is subject to a stretching step by step. Thedi== ameter of the guiding groove '7 is thus the smallest and thediameter increases from guiding groove to guiding groove. The threadleaving the guiding groove 14 is either ted to a spool or roller, to aspinning pot or in using the continue process is passed to the severaltreating baths.

In the first form of execution the roller 2 lies outside the spinningbath and roller 3 inside the spinning bath, the level of which is shownat 16. When at least one roller is immersed in the spinning bath and atleast one roller is positioned outside the spinning bath, the filamentspass into and out of the precipitating bath a plurality of times, sothat in its passage through the air after each immersion, the filamentsmay, to a certain extent, compensate in themselves for any stressapplied by the drawing means before being wound on the take-up device.The result is to effect a step by step coagulation with intermediatecompensation for any stress on the threads taking place. The revolutionof the rollers is actuated by the thread passing over it; they can,however, be driven positively.

According to Fig. 3 two guiderods 1'7 for the thread to be stretched arepositioned in front of a roller in order to cause in a manner known initself the stretching to take place at a certain section of the thread.

.Should the braking resistance of the roller caused by the bath orhearing friction necessary for stretching the thread in the shown formsof execution be not sufllcient, then a brake weight or turbulence brakeor the like may be used. In leaving the guiding groove 14 a subsequentstretching or slackening can be given to the thread by the drawing-01fmember.

In machines, in which the thread is collected on a rigid base (spool orroller) it is advisable to interpose according to Fig. 2 a positivelydriven guiding or drawing ofi roller 18 between the apparatus accordingto the invention and the winding organ 32, around which the thread isentwined one or more times for the purposes of a good hold. It can havea slower, the same or a greater drawing of! speed than that whichcorresponds to the speed of the thread running on to the spool orroller.

The apparatus according to Figs. 4 and 5 has only single rollers. Therollers 19, 21, 23 and the rollers 20, 22 and 24 are united into onegroup. The two last mentioned rollers of each group are excavated on oneside in such a way that they somewhat overlap the rollers adjacent tothis side. The rear side of the roller protruding into this cavity iskept at a corresponding diameter. In order that a small as possiblefriction surface between the rollers is supplied, the rollers 21-24 areeach provided with a projection 25.

The rollers run loosely on bolts 26, which are carried by a holder 27.This holder is clamped by means of the screws 28, 29 to the pipe 31ending in the spinning jet 30. In Fig. 6 is illustrated the manner inwhich a successive stretching action may be imparted to the thread bygiving it a greater lineal speed at each spaced point. The thread isshown extruding from the spinneret l5 and passing it to the smallestgroove 7 of the roller 2 and then carrying it to the larger groove 10 ofthe roller 3, back to groove 11 05. roller 2 and then around groove 14of roller 3, the grooves 7, 10, 11, and 14 being of successivelyincreasing diameters and traveling at greater peripheral speeds.

In Fig. '7 the thread first passes around the largest groove 13 o!roller 2, then to a groove 12 of smaller diameter, on roller 3 back toroller 2 and passing around groove 9, which is of smaller diameter thangroove 12, and finally passes around groove 14 which is smallest of all.This arrangement allows a successive contraction oi. the thread becausesuccessive grooves in its path are traveling at successively slowerspeeds.

In Fig. 8 the thread is passed first to groove 13 and then to groove 14,which travels at a slower peripheral speed, then to groove 11 travelingat a higher speed, to groove 12 traveling at a? lower,

and so on to grooves 9, 10, 7, and finally around groove 8, wherebyhigher and lower speeds are alternately imparted to the thread.

- thread.

what I claim is 1. In .the manufacture of artificial silk fromcellulosic solutions, the steps of extruding the cellulosic solutions,the steps of extruding the thread, drawing it successively over surfacesdriven by said thread, each of said surfaces having different diameterportions, repeating the drawing of the thread at least onceoverdifferent portions of the said surfaces in such a manner that eachsuccessive portion contacted by the thread will have a greaterperipheral speed, thereby imparting a progressive stretch to the thread.

3. In the manufacture of artificial silk from cellulosic solutions, thesteps of extruding the thread, drawing it successively over surfacesdriven by said thread, each of said surfaceshaving different diameterportions, repeating this drawing of the thread at least once overdifferent portions of the said surfaces in such a manner as to impartdifferent linear speeds to the thread when it passes over the saidsurfaces.

4. In the manufacture of artificial silk from cellulosic solutions, thesteps of extruding the thread, drawing it successively over surfacesdriven by said thread, each of said surfaces having different diameterportions, repeating this drawing of the thread at least once overdifferent portions of the said surfaces in such a manner that eachsuccessive portion contacted by the thread will have a lesser peripheralspeed, thereby resulting in an increasing contraction of the 5. In themanufacture of artificial silk from cellulosic solutions, the'steps ofextruding the thread, stretching it and contracting it while in plasticcondition by giving it different linear.

'by drawing it over surfaces driven solely by said thread.

7. A device of the class described comprising at least two shafts,freely rotating guiding rollers on the said shafts, a spinning pipe andmeans for movably connecting the said shafts with the said spinningpipe.

8. A device of the class described comprising at least two shafts,several freely rotating guiding rollers on each of the said shafts, aholder carrying the said shafts, a spinning pipe and clamping means formovably connecting the said holder with the said pipe.

9. In the manufacture of artificial silk from cellulosic-solutions, thesteps of extruding the thread, imparting to it while inplastic'condition different linear speeds at spaced points in its pathof'travel, comprising drawing it successively over surfaces driven bysaid thread, each of said surfaces having different diameter portionsand at least one of said surfaces immersed in a bath calculated to aidin the precipitation of the filaments, repeating this drawing at leastonce over different portions of the said surfaces. 1

10. In the manufacture of artificial silk from cellulosic solutions, thesteps of extruding the thread, 'drawing it successively over surfacesdriven by'said thread, at least one of said surfaces having differentdiameter portions, repeating this drawing of the thread'at least .onceover different portions of the said surfaces in such a manner as toimpart different linear speeds to the thread when it passes over thesaidsurfaces,

and passing it to a collecting device under de-' creased tension.

11. In the manufacture of artificial silk from cellulosic solutions, thesteps of extruding the thread, imparting to it while in plasticcondition different linear speeds at spaced points in its path oftravel, comprising drawing it successively over surfaces driven by saidthread, each of said surfaces having different diameter portions and atleast one of saidsurfaces immersed in a bath calculated to aid in theprecipitation of the filaments, repeating this drawing at least onceover different portions of the said surfaces, and passing it to acollecting device under decreased tension.

12. In the manufacture of artificial silk from cellulosic solutions, thesteps of extruding the thread, drawing it successively over surfacesdriven by said thread, at least one of said surfaces having differentdiameter portions, said surfaces mounted in-part in and in part out of abath calculated to aid in the precipitation of as Y the thread,repeating this drawing of the thread at least once over differentportions of the said surfacesin such a manner as to impart differentlinear speeds to the thread when it is drawn over the said surfaces.

13. In the manufacture of artificial silk from cellulosic solutions, thesteps of extruding the thread, drawing it successively over surfacesdriven by said thread, at least one of said surfaces having differentdiameter portions, said surfaces mounted in part in and in part out of abath calculated to aid in the precipitation of the thread, repeatingthis drawing of the thread at least once over different portions of thesaid surfaces in such a manner as to impart different linear speeds tothe thread when it is drawn over the said surfaces, and passing it to acollecting device under decreased tension.

14. Apparatus for use in the manufacture of artificial silk comprisingfreely rotatable rollers, at least one of which has thread engagingsurfaces of different diameters to impart different linear speeds atspaced points in its path of travel to a thread drawn alternately fromone of the said rollers to another a plurality of times, and' means fordrawing the thread thereover.

15. Apparatus for use in the manufactureof artificial silk comprisingfreely rotatable rollers having thread engaging surfaces of differentdiameters to impart different linear speeds at spaced points to a threadin its path of travel when said thread-is drawn alternately from thesurfaces of one roller to the surfaces .of another roller a plurality oftimes, and'means for drawing the thread thereover.

16. Apparatus for manufacture of artificial silk comprising a spinningnozzle for extruding the thread, freely rotatable rollers in spacedrelation and driven by the thread passing thereover, said 4 rollershaving guiding surfaces of different diameters so arranged that, whenthe thread is passed alternately from the surfaces of one roller to thesurfaces of another roller a plurality of times, each successive guidingsurface in the path of the thread has a greater diameter than thepreceding one, and means for drawing the thread thereover.

17. Apparatus for manufacture of artificial silk comprising a spinningnozzle for extruding the thread, freely rotatable rollers in spacedrelation and driven by the thread passing thereover, said rollers havingguiding surfaces, of different diameters so arranged that, when thethread is passed alternately from the surfaces of one roller to thesurfaces of another roller a plurality of times, each successive guidingsurface in the path of the thread has a different diameter than thepreceding one, and means for drawing the thread thereover.

18. Apparatus for manufacture of artificial silk comprising a spinningnozzle for extruding the thread, freely rotatable rollers in spacedrelation and driven by the thread passing thereover, said rollers havingguiding surfaces of different diameters so arranged that, when thethread is passed alternately from the surfaces of one roller to thesurfaces of another roller a plurality of times, each successive guidingsurface in the path of the thread has a lesser diameter than thepreceding one, and means for drawing the thread thereover.

19. Apparatus for use in the manufacture of artificial silk comprisingfreely rotatable rollers having thread engaging surfaces of differentdiameters to impart different linear speeds at spaced points to a threadin its path of travel when said thread is drawn alternately from thesurfaces of one roller to the surfaces of another roller a plurality oftimes, means for drawing the thread at a constant rate, and a take-updevice for collecting the thread.

20. Apparatus for manufacture of artificial silk comprising a spinningnozzle for extruding the thread, freely rotatable when in spacedrelation and driven by the thread passing thereover, said rollers havingguiding surfaces of different diameters so ar-,

ranged that, when the thread is passed alternately from the surfaces ofone roller to the surfaces of another roller a plurality of times, eachsuccessive guiding surface in the path of the thread has a differentdiameter than the preceding one, tension creating guide rods positionedin advance of the first freely rotatable roller for deflecting thecourse of the thread, and means for drawing the thread from said guiderollers at a constant rate. a

21. Apparatus for use in the manufacture of artificial silk comprisingfreely rotatable rollers having thread engaging surfaces of differentdiameters to impart different linear speeds at spaced points to a threadin its path of travel when said thread is drawn alternately from thesurfaces of one roller to the surfaces of another roller a plurality oftimes, means for drawing the thread at a constant rate, a rotatablereceiver for collecting the threads, and means for driving said receiverat a lesser peripheral speed than said drawing device.

22. Apparatus for manufacture of artificial silk having a spinningnozzle for delivering thread forming material to a coagulating bath anda means for collecting the thread, in combination with a plurality offreely rotatable rollers having thread engaging surfaces of varyingdiameters disposed intermediate the spinning and the collecting means,at least one of said rollers contacting with the coagulating bath, saidrollers adapted to be driven by the thread passing thereover and toimpart different linear speeds when it is passed alternately from theguiding surfaces of one roller to the guiding surfaces of another aplurality of times.

23. An apparatus for the manufacture of artificial silk having aspinning nozzle for delivering thread forming material to a coagulatingbath and a means for collecting the thread; in combination with a pairof spaced freely rotatable rollers disposed intermediate the-spinningnozzle and the collecting means, said rollers having guiding grooves ofdifferent diameters and driven by the thread passing thereover, saidguiding grooves being so arranged that, when the thread is passedalternately from the grooves of one roller to the grooves of anotherroller a plurality of times, each successive guiding groove in the pathof the thread has a different diameter than the preceding one.

24. An apparatus for the manufacture of artificial silk having aspinning nozzle for delivering thread forming material to a coagulatingbath and a means for collecting the thread, in combination with a pairof spaced freely rotatable rollers disposed intermediate the spinningnozzle and the collecting means, said rollers having guiding grooves ofdifferent diameters and driven by the thread passing thereover, saidguiding grooves being so arranged that, when the thread is passedalternately from the grooves of one roller to the grooves of anotherroller a plurality of times, each successive'guiding groove in the pathof the thread has a lesser diameter than the preceding one.

25. An apparatus for the manufacture of artificial silk having aspinning nozzle for delivering thread forming material to a coagulatingbath and a means for collecting the thread, in combination with a pairof spaced freely rotatable rollers disposed intermediate the spinningnozzle and the collecting means, said rollers having guiding grooves ofdifferent diameters and 125 driven by the thread passing thereover, saidguiding grooves being so arranged that, when the thread is passedalternately from the grooves of one roller to the grooves of anotherroller a plurality of times, each successive guiding groove 130 in thepath of the thread has a greater diameter than the preceding one.

26. Apparatus for the manufacture of artificial silk having a spinningnozzle for delivering thread forming material to a. coagulating bath 135and means for collecting the thread, in combination with a plurality offreely rotatable rollers, each having a plurality of guiding grooves,and disposed intermediate the spinnerette and the collecting means, atleast one of said rollers

